(a) Technical Field of the Invention
The present invention generally relates to power adaptors, and more particularly to a power adaptor whose prongs can be retracted and hidden inside the adaptor body.
(b) Description of the Prior Art
Most consumer electronic devices require a power adaptor converting the 110V or 220V AC power into a desired voltage for the device to properly function. As shown in FIG. 6, a conventional power adaptor (e.g., one for a notebook computer) mainly contains an adaptor body A1 connecting two power cables A2. At an end of a first power cable A2, there is a plug A21 for plugging into a power outlet or wall socket for introducing the AC power into the adaptor body A1 for rectification and regulation. The converted voltage is then supplied to the electronic device via the second power cable A2. At an end of the second power cable A2, there is another plug A22 for plugging into the electric device. There are also some adaptors where there is no first power cable A2 and the plug A21 is directly and fixedly provided on the adaptor body A1.
These conventional power adaptors have a number of shortcomings. First of all, for the type of adaptors where the plug is provided on the adaptor body, the protrusion of the plug turns the adaptor body into an irregular shape, which is less convenient to store or carried. On the other hand, the prongs of the plug could easily be deformed when the adaptor is stored or carried with other heavy objects, or the sharp prongs of the plug may scratch or even damage the object or pierce through the bag carrying the adaptor.
Secondly, for the type of adaptors with two power cables, the addition of an extra power cable inevitably increases the product cost. Additionally, the power cables are usually of a certain length for operating the device over a certain distance from the power source. As the lengthy cables are often tangled together, the management of the power cables is always quite troublesome.